HVAC hose leak

[Everlastinqs]

Started hearing a sound similar to when the heats on high , only from the passenger side. Doesn’t go away when controls are fully off. Quieter when stopped, gets louder with speed. Took it to a shop they said I have a hvac leak somewhere just air in the closed system. Not losing any, however when the heats on high it smells like coolant. Shop couldn’t diagnose further without taking dash apart. Anything I could check out without taking the dash apart or should I let shop handle it?

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[DaltonGang]

Sounds like things are going to need to be taken apart, unless you have a long bore scope, and can snake it towards the heater core area, and all areas behind the dash.

 

[mwilk012]

You’re low on coolant.

You posted this like you’re looking for an air leak. It seems like you don’t understand that engine coolant flows through the heater core to produce heat. You’re hearing air bubbles in the pipes due to being low on engine coolant.

Which engine do you have?

 

[roaniecowpony]

I wouldn't let your Mario brothers mechanics take your dash apart until they pressure test your coolant system and it fails to hold pressure and they eliminate a leak under the hood. It's a very intrusive process to take the dash out and I would bet things like wiring clips, screws, fit, or even worse don't get back together correctly 100%.

Only if both:
1) a leak exists in the coolant system, AND
2) they eliminate the possibility of that leak being under the hood,
would I allow them to take the dash apart to chase a heater core leak.

OR, if they leak test the air conditioning system and
1) it fails to hold pressure, AND
2) the eliminate any possibility of leaks under the hood,
would I allow them to take the dash apart to chase an air conditioning evaporator leak.

AND, you''re absolutely sure these are the experts you want gutting your dash. There are a lot of wires, and electronic components in and behind the dash. It's kind of the nerve center of your highly complex jeep. Make sure you're confident in your shop's abilities.

 

[Everlastinqs]

You’re low on coolant.

You posted this like you’re looking for an air leak. It seems like you don’t understand that engine coolant flows through the heater core to produce heat. You’re hearing air bubbles in the pipes due to being low on engine coolant.

Which engine do you have?

3.6. Coolant in the reservoir isn’t dropping at all. The place I took it to told me it was some kind of air leak. He specifically said a vacuum leak in the hvac but I know a vacuum leak is something totally different and jeep hasn’t thrown any codes. I didn’t think that was how it works but I’m not all too mechanically inclined with those kinds of things.

 

[mwilk012]

The

3.6. Coolant in the reservoir isn’t dropping at all. The place I took it to told me it was some kind of air leak. He specifically said a vacuum leak in the hvac but I know a vacuum leak is something totally different and jeep hasn’t thrown any codes. I didn’t think that was how it works but I’m not all too mechanically inclined with those kinds of things.

If you hear the noise with the blower off, it isn’t air.

 

[Everlastinqs]

The

If you hear the noise with the blower off, it isn’t air.

Back in August, I had a dealership leave my coolant cap off after an oil change, my fault for not checking, then everything boiled out. I took it back to them and they said they removed air from the system from me refilling it, cleaned everything up and said everything was fine. Should I be taking this back to them as something possibly caused by this situation then? Even 3 months later? Or likely a separate issue?

 

[mwilk012]

Back in August, I had a dealership leave my coolant cap off after an oil change, my fault for not checking, then everything boiled out. I took it back to them and they said they removed air from the system from me refilling it, cleaned everything up and said everything was fine. Should I be taking this back to them as something possibly caused by this situation then? Even 3 months later? Or likely a separate issue?

Separate issue.

 

[Everlastinqs]

Separate issue.

Thanks

 

[mwilk012]

Coolant leaks on a JL leave horrible pink stalactites behind and are very easy to find.

 

[roaniecowpony]

3.6. Coolant in the reservoir isn’t dropping at all. The place I took it to told me it was some kind of air leak. He specifically said a vacuum leak in the hvac but I know a vacuum leak is something totally different and jeep hasn’t thrown any codes. I didn’t think that was how it works but I’m not all too mechanically inclined with those kinds of things.

I'm not aware of any vacuum systems behind the dash. Maybe @mwilk012 or @alphawolff can weigh in on that comment. But, if there are no vacuum systems back there, it calls into question the competency or honesty of this shop. Neither of which you would want to be in question if you're opening your wallet to them.

 

[roaniecowpony]

I have seen vacuum leaks in the brake booster which can be heard from inside the cab. The brake booster is mounted on the firewall, under the hood, directly above the brake pedal. It's a round metal container with a rubber diaphram inside. There is a vacuum line running to it and it can develop leaks from either the connections of the lines or internally.

You might listen closely to this area for indications of the noise.

The second picture is a JL and where the brake booster is located. The first picture is just an example from another model, but it shows a typical brake booster (the big round metal can) and a typical vacuum hose and fitting. The leaks are often enough where the fitting goes into the can, and can be just as simple as it falling out and needing to be pushed in, or it can be more complicated.

 

[mwilk012]

I'm not aware of any vacuum systems behind the dash. Maybe @mwilk012 or @alphawolff can weigh in on that comment. But, if there are no vacuum systems back there, it calls into question the competency or honesty of this shop. Neither of which you would want to be in question if you're opening your wallet to them.

There are none.

 

[Everlastinqs]

I have seen vacuum leaks in the brake booster which can be heard from inside the cab. The brake booster is mounted on the firewall, under the hood, directly above the brake pedal. It's a round metal container with a rubber diaphram inside. There is a vacuum line running to it and it can develop leaks from either the connections of the lines or internally.

You might listen closely to this area for indications of the noise.

The second picture is a JL and where the brake booster is located. The first picture is just an example from another model, but it shows a typical brake booster (the big round metal can) and a typical vacuum hose and fitting. The leaks are often enough where the fitting goes into the can, and can be just as simple as it falling out and needing to be pushed in, or it can be more complicated.

Just checked this out. All the connections feel fine and I’m not hearing it from that area. Sound is definitely on the passenger side, but only heard from inside the cab

 

[jaymz]

I had a very similar symptom recently and it drove me nuts for a few days. Sounded like a rather large vacuum leak. Turns out that the floor drain plug cover on the passenger side floor mat came out. I put it back in and the noise went away.

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